Automatic apparatus for sewing a seam of a predetermined configuration

ABSTRACT

A sewing machine including means for automatically sewing a seam of a particular configuration. Fabric clamp means are guided past the sewing needle by a guide means which simultaneously imparts a rectilinear and a rotative motion to the clamp means.

O United States Patent [151 3,653,347 Bianchi [451 A r. 4 1972 [54] AUTOMATIC APPARATUS FOR [56] References Cited SEWING A SEAM OF A UNITED STATES PATENTS PREDETERMINED CONFIGURATION 1,649,319 11/1927 Molyneux ..1l2/l21.15X [72] inventor: Nereo Blanch], Pavia, Italy 1 942 12 H1934 Sommer 3 228 364 1/1966 Kremer et a1.

h I [73 1 Ass'gnee p A Pam my 3,474,747 10/1969 Nolles [22] Filed: July 16, 1970 3,522,783 8/1970 Pollmeier ..1l2/121.15

[211 App) 55314 Primary Examiner-James R. Boler Attorney-Stevens, Davis, Miller & Mosher [30] Foreign Application Priority Data [57] ABSTRACT I l ..32418 A July 1969 ta y /69 A sewing machine including means for automatically sewing a seam of a particular configuration. Fabric clamp means are [52] US. Cl guided past the Sewing needle by a guide means which Simul [51] Int. Cl. taneously imparts a rectilinear and a relative motion to the [58] FieldofSearch ..112/2,12l.12,l21.11,12l.l5, clam p means. 112/102, 204, 205

3 Claims, 4 Drawing Figures PATENTEDAPR 4 912 3, 653 347 SHEEIl0F3 v om mm; mmwhmr mm mm hm" mm INVENTOR NEREO BIANCHI PATENTEBAPR 4 I972 SHEET 2 [IF 3 FIG.

PATENTED APR 4 I972 SHEET 3 [IF 3 AUTOMATIC APPARATUS FOR SEWING A SEAM OF A PREDETERMINED CONFIGURATION The present invention relates to an automatic apparatus for sewing seams of a given profile, consisting of a sewing machine, a fabric holding clamp and means for actuating same, means for guiding said clamp below the needle of said sewing machine in accordance with a predetermined law of motion and means for regulating and controlling the successive phases of the entire operating cycle.

In particular, said shaped stitches are of the type adapted to obtain pleats on certain articles of clothing such as shirts to impart to them esthetic and functional characteristics. These pleats, which are commonly known as darts, are usually formed of two consecutive linear segments slightly shifted in their direction or continuous sections of small curvature and in all cases assume a course close to linear.

The object of the present invention is to provide actuating means, guide means and regulating and control means having characteristics adapted to simplify the apparatus of the type indicated both in cost and in operation.

In order to achieve this object, the technical problem to be solved was to use a single simple means for actuating the fabric clamps and to use in combination with same guide means for said clamp which are just as simple in order to obtain the seam of the desired shape.

The solution of the technical problem set forth above is characterized by the fact that the said actuating means is composed of a driving cylinder which by its shaft actuates a carriage which is displaceable on linear guides and bears the fabric clamp which has a groove of the shape of the seam to be made coupled to a boss fastened on the base of the sewing machine at the hole of the needle plate and is hinged at its one end to a point on said carriage, the absolute movement of the clamp during the operation of the apparatus being thus composed of a linear translation and a rotation around a point thereon. In particular the said drive cylinder is formed of a hydropneumatic unit composed of a pneumatic actuating cylinder and an oil-controlv cylinder adapted to make the speed of displacement of the said shaft connected to the clamp-holding carriage uniform and adjustable.

Another characteristic of the invention, combined with the particular systems of actuation and guidance of the fabric clamp, relates to the carrying out of sewing operations to be effected on the end portions of the darts. However, in order to form the sewing of the darts, it is necessary to effect sections of double stitches at the ends thereof. It is therefore necessary to obtain, at the start and at the end of the sewing of a dart, namely at the end thereof, the reversal of the movement of the clamp for a short period of time necessary for the effecting of the fastening stitches. Furthermore, for better utilization of the apparatus which forms the object of the invention, there is not provided at the end of the sewing an empty return of the clamp into the starting position but the subsequent stitches start alternately from opposite ends of the path of the carriage so that the stopping point of one dart coincides with the starting point of the next.

In order to obtain this, the means for the regulating and control of the phases of the operating cycle comprise opposing elements carried along in the movement of the carriage only in the end portions of its stroke and interfering with corresponding feelers which actuate valves at the end points of the darts, said valves being arranged to effect the reversal of the motion of the clamp at the start of the sewing of the darts and to effect the reversal of the motion of the clamp and the stopping thereof with a small adjustable delay at the end of the sewing of the dart and to predetermine the direction of motion of the next dart in the direction opposite the previous one.

In order to obtain the adjustable delay, retarders are provided connected to said valves and composed of a base and of a pin which is connected to the feeler actuating the valves and connected in air-tight manner with a cavity provided in said base to penetrate into same against the action of a return spring when the opposing element actuates said feeler; the

return time of the said pin outside of said cavity and therefore the switching of the valve for the control of the clamp is determined by the regulation of the section of an opening which places the bottom of said cavity in communication with the outside.

Other characteristics and advantages will become evident from the'description of the invention and from the accompanying drawings in which:

FIG. 1 shows an overall view of the apparatus which is the object of the invention;

FIG. 2 shows a detail of the apparatus of FIG. 1;

FIG. 3 shows the pneumatic diagram with the arrangement of the various drive, regulating and control members, and

FIG. 4 shows schematically the form of sewing which can be carried out with the apparatus of FIG. 1.

Referring to FIG. 1, 10 is a table on which there rests a sewing machine 11 of which there can be noted the base 12, the upright 13 and the head 14. From this head 14 there emerges a needle bar 15 bearing a needle 16. In the lower part of the table 10, resting on a profiled part 17, there is the footboard 18 which, via the rods 19 and 20, acts on two three-way valves 71 and 83 (FIG. 3) adapted to control the actuation of the apparatus, as will be described below.

On the top 21 of the table 10 there are fastened two plates 22 and 23 bearing the shafts 24, 25 and 26. The shaft 26 is supported by two bushings 27 and 28 provided on the plates 22 and 23 respectively and bears at its two ends a part 29 adapted to cooperate with the rollers 30 supported by the levers 31 of the two three-way valves 32 and 33.

On the central portion of the shaft 26 there is secured a bar 34 having threaded holes 35 in which there are screwed blocks 36 adapted to regulate the length of the dart, as will be explained in further detail below. Between the ends of the bar 34 and the bushings 27 and 28 there are arranged the springs 37. On a bar 39 fastened on the top 21 of the table 10 there is pivoted at 40 a U-shaped element 41 against which there rests a head 42 of a hydropneumatic unit 43 composed of a pneumatic cylinder 44 and an oil control cylinder 45 adapted to make the speed of displacement of the shaft 46 of said hydropneumatic unit connected to a carriage 47 adjustable.

The regulation of the speed of displacement of the said shaft 46 is provided by a flow regulator (FIG. 3) placed between the heads 42 and 121 of the oil control cylinder 45. A bushing 48 is fastened adjustably to one end of the carriage 47 by means of a tie 49. A pin 50, which is free to rotate in the bushing 48, bears at the top a block 51 to which there is fastened the lower plate 52 of the fabric clamping clamp 53. The plate 52 bears two single-acting pneumatic cylinders 54 and 55 the rods 56 of which are fastened to a plate 57 forming the upper part of the clamp 53.

The carriage 47, during its translation controlled by the shaft 46, moves along the shafts 24 and 25 which prevent the rotation thereof and carries the clamp 53 along with it in its movement. A boss 58 placed on the base of the machine 12 at the hole of the needle plate 22 connects with a groove 123 (FIG. 2) provided in the plate 52, reproducing the shape of the dart, and permitting transverse oscillations of the clamp 53 which is free to rotate with its pin 50 in the bushing 48. In the vicinity of the end of the stroke of the carriage 47 a finger 59 of the carriage 47 which can be seen in FIG. 3 comes into contact with the block 36 and, overcoming the strength of one of the springs 37, depending on the direction of displacement, carries along with it the bar 34 and accordingly the shaft 26 fastened to same in the direction towards the end of the shaft 46 so that the part 29 comes into contact with the roller 30 of one of the valves 32 and 33, opening it. A ring 38 rigidly connected with the shaft 26 permits the said shaft to rotate so as to present to the finger 59 of the carriage 47 the surface of the bar 34 with the blocks 36 placed at the distance corresponding to the length of the darts which it is desired to obtain.

Referring to FIG. 4, the dart which is to be made is formed of two linear sections of slight inclination with respect to a horizontal line and has at its two ends sections of double stitches having the purpose of stopping the seam in the initial section and in the final section. Furthermore, it is advisable to start the sewing on the inside of the dart since the end points thereof extend. normally to the edge of the fabric being worked and, due to inevitable lack of precision in positioning, it may happen that the first stitches are made outside the fabric if the sewing is started at the ends of the dart. The sewing of the dart then takes place starting from the point 1 and upon arriving at the point 2 there is caused a reversal of the movement ofthe clamp, the path from 2 to l is reduced and is continued to point 3. At this point there is another reversal of the movement of the clamp to double the stitching from the point 3 to the point 4. The two seams are perfectly superimposed even though, for ease in description, they have been shown separately in FIG. 4.

At the start of the operation when the main compressed air conduit is open, the compressed air passes from the feedline 60 through a solenoid 61 (FIG. 3) into the air filter 62, the pressure gauge 63 and the lubricator 64. Through the conduit 65 the compressed air arrives at a three-way valve 66 which is closed. Through the conduit 68 the air which comes from the lubricator 64 via a four-way valve 69 and the conduit 70 arrives at a two-way valve 71 which is opened when the footboard 18 is in the position of rest shown in FIG. 3. Via the valve 71, a flow regulator 72, a fast discharge valve 73, a plenum chamber 74 and a conduit 75, the air arrives at a pilot 76 which opens the valve 66. The air of the conduit 65, through the valve 66 which is now open and the conduit 67 arrives at the single-acting cylinders 54 and 55 which in this way raise the plate 57 of the clamp 53. From the rapid discharge valve 73, via the conduit 77, the four-way valve 78, the conduit 79 and the switching valve 80, the air arrives at a pilot 81 which switches the four-way valve 82. The air which emerges from the lubricator 64 via the conduit 124 arrives at a threeway valve 83 which is closed and via the branch 84 at the three-way valves 32 and 33 which are closed. Now the operator introduces between the plates 52 and 57 of the clamp 53 the rear part of the shirt and presses the board 18 ihto a position intermediate between the valves 71 and 83. The valve 71 closes, interrupting the flow of air in the conduits 77 and 75. The interruption of the flow of air into'the conduit 75 causes the closing of the valve 66 by the pilot 76 and the cylinders 54 and 55 discharge with the consequent closing of the clamp 53 which clamps the fabric between the plates. By further pressing the footboard 18 until the valve 83 is opened, the air passing through the conduit 85 and theflow regulator 86 arrives at the pilot 87 which switches the valve 69. The air which is present in the conduit 68 passes through the valve 69, the conduit 88, the valve 82, the conduit 89, the rapid discharge valve 90 and arrives in the head 42 of the cylinder 44 causing the rod 46 to move in the direction of the arrow, it carrying along with it the carriage 47 which bears the clamp 53 so as to obtain the sewing from 1 to 2 (FIG. 4). At the same moment the air which passes through the valve 69 through a conduit 91, a flow regulator 92 and then through a rapid discharge valve 93, a plenum chamber 94, a rapid discharge valve 95, arrives at the microswitch 96 which controls the starting of the sewing cycle. The said microswitch 96 remains actuated for the entire duration of the cycle. During the sewing from point 1 to point 2 shown in FIG. 4, the finger 59 comes into contact with the block 36, axially displacing the bar 34 and ac cordingly the part 29 which comes to interfere with the roller of the valve 33, opening the latter.

The air of the valve 33, via the conduit 97 and the switch valve 98, arrives at the pilot 99 which switches the valve 82; the same air which passes from the valve 33 via the conduit 100 arrives at the pilot 101 which switches the valve 78 to prepare it for the subsequent operations. With the switching of the valve 82, the air of the conduit 88, passing through the conduit 102 and the rapid discharge valve 103, enters into the head 104 of the cylinder 44, displacing the rod 46 in the direction opposite that of the arrow A so as to obtain the sewing from the point 2 to the point 3 of FIG. 4. During the sewing from point 2 to point 3, the bar 34, no longer acted on by the finger 59, returns into its position of rest by means of the return spring 37. In this way the roller 30 is no longer in contact with the part 29 and the valve 33 closes, discharging the conduits 97 and 100, the air of which, via the conduit 114, the switching valve 109, the conduit 110 and the needle valve 115, is discharged into the atmosphere, the pilot 125 notsucceeding in switching the valve 69, since the pilot 87, when the footboard 18 has been released, is still not discharged, being connected to the flow regulator 86 which regulates the flow during the discharge of the conduit 85. In the proximity of point 3 the finger 59 of the carriage 57 engages the block 36 axially displacing the bar 34 in such a manner that the part 29 comes into contact with the roller 30 of the valve 32, opening it. The air which is present in the conduit 34 via the valve 32, the conduit 105 and the switch valve arrives at the pilot 81 and switches the valve 82, while by means of a conduit 106 connected with the conduit the air arrives at the pilot 107 which switches the valve 78. The air of the conduit 88, via the valve 82, the conduit 89 and the rapid discharge-valve 90, enters the head 42 of the cylinder 44, displacing the rod 46 in the direction indicated by the arrow A until it arrives at the point 4, since the bar 34 not being acted on any longer by the finger 59, returns into its position of rest by means of the return spring 37. In this way the roller 30 is no longer in contact with the part 29 and the valve 32 closes, placing the conduit 105 in discharge, the air of which arrives via the conduit 108, theswitching valve 109 and the conduit 1 10 at the pilot which switches the valve 69, overcoming the resistance of the pilot 87. The switching of the valve 69 causes the interruption of the flow of air in the conduits 88 and 91, in this way stopping the clamp 53 and stopping the sewing machine. At the same time, the air, via the conduit 70 and the valve 71 which is open, the flow regulator 72, the rapid discharge valve 73, and the plenum chambers 74 and 112 actuates the microswitch 113 which controls the thread cutter and via the conduit 75 actuates the pilot 76 which opens the valve 66, permitting the flow of air into the conduit 67 which actuates the cylinders 54 and 55 which raise the plate 57 of the camp 53, thus permitting the removal of the sewn fabric.

Via the conduit 77 and the valve 78, the machine is prepared for the next sewing cycle at which the sewing will start at point 4 and terminate at 1. The closing clamps of the paths 3-4 and 2-1 can be made of variable length to satisfy given requirements in the garment industry. For such purpose there are provided on the valves 32 and 33 two retarders 126 formed by a base 127, a pin 28 which can slide against the action of a spring 129 within a cavity provided on the upper surface of the base 127. The pin 128 has a head 130 connected to the curved end of a shaft 131 connected to the arm 31 of the valves 32 and 33. The cavity within which the pin 128 slides communicates with the outside through a hole, not shown, the passage opening of which can be regulated by means of a screw 132. When the part 29, after having pressed against the roller 30, at the end of the sewing of the end sections of the dart, releases it, pulled back by the spring 37 into its dart, releases it, pulled back by the spring 37 into its position of rest, the valve 32 or 33 which has been opened by the part 29 and has thus reversed the direction of movement of the clamp must remain open for a certain period of time in order to obtain the double closing seam, since the closing of the said valve causes the stopping of the machine and the stopping of the movement of the clamp. By regulating by means of the screw 132 the opening which places the bottom of the cavity of the base 127 in communication with the outside there is obtained a faster or slower return of the pin 128 by the spring 129 and accordingly an adjustable time of rise of the arm 31 which determines the desired retardation in the closing of the valve.

1 claim:

1. Automatic apparatus for producing seams of a given profile comprising: a sewing machine having a sewing needle, a needle plate having an opening therein, a carriage slidable on rectilinear guides, a fabric-holding clamp mounted on said carriage and actuating means for same, means for guiding said clamp below the needle of said sewing machine in accordance with a pre-determined law of motion, characterized by the fact that the said actuating means comprises a driving cylinder and piston which actuates said carriage along said guides, said clamp having a groove of the shape of the seam to be made, a boss fastened on the base of the sewing machine and engaged with said groove at said opening of the needle plate, means pivotally connecting said clamp at its one end to a point of said carriage, the resultant motion of the clamp during the operation of the apparatus being thus composed of a linear translation and a rotation around a point thereof.

2. Apparatus according to claim 1, characterized by the fact that the said actuating means comprises a hydropneumatic unit and a movable shaft controlled thereby which is co-operatively engaged with said carriage, composed of a pneumatic actuating cylinder for driving said shaft and a pneumatic oil control cylinder for adjustably controlling the speed of displacement of said shaft.

3. Apparatus according to claim 1, including means for regulating the movements of said clamp which means comprise valves for controlling the air flow to said pneumatic cylinder and opposing parts carried along by the movement of the carriage only in the end portions of its strokes and further including abutting suitable feelers which actuate the valves at the end points of the darts, said valves being arranged to effect a reversal of motion of the clamp upon the commencement of the sewing of the dart and to effect the reversal of the movement of the clamp and the stopping thereof with a small delay, retarding members located at positions corresponding to the end of the sewing of the dart for effecting said delay, said valves also being adapted to determine the direction of movement of the next dart in the direction opposite the preceding direction. 7 

1. Automatic apparatus for producing seams of a given profile comprising: a sewing machine having a sewing needle, a needle plate having an opening therein, a carriage slidable on rectilinear guides, a fabric-holding clamp mounted on said carriage and actuating means for same, means for guiding said clamp below the needle of said sewing machine in accordance with a pre-determined law of motion, characterized by the fact that the said actuating means comprises a driving cylinder and piston which actuates said carriage along said guides, said clamp having a groove of the shape of the seam to be made, a boss fastened on the base of the sewing machine and engaged with said groove at said opening of the needle plate, means pivotally connecting said clamp at its one end to a point of said carriage, the resultant motion of the clamp during the operation of the apparatus being thus composed of a linear translation and a rotation around a point thereof.
 2. Apparatus according to claim 1, characterized by the fact that the said actuating means comprises a hydropneumatic unit and a movable shaft controlled thereby which is co-operatively engaged with said carriage, composed of a pneumatic actuating cylinder for driving said shaft and a pneumatic oil control cylinder for adjustably controlling the speed of displacement of said shaft.
 3. Apparatus according to claim 1, including means for regulating the movements of said clamp which means comprise valves for controlling the air flow to said pneumatic cylinder and opposing parts carried along by the movement of the carriage only in the end portions of its strokes and further including abutting suitable feelers which actuate the valves at the end points of the darts, said valves being arranged to effect a reversal of motion of the clamp upon the commencement of the sewing of the dart and to effect the reversal of the movement of the clamp and the stopping thereof with a small delay, retarding members located at positions corresponding to the end of the sewing of the dart for effecting said delay, said valveS also being adapted to determine the direction of movement of the next dart in the direction opposite the preceding direction. 